Three strikes law

In the United States, habitual offender laws (commonly referred to as three-strikes laws) were first implemented by states then by the federal government in 1995. They mandate courts impose harsher sentences on those convicted of an offense if they have been previously convicted of two prior serious criminal offenses. The laws were designed to keep people who had shown a predliction to committing crimes in prison and away from potential victims.

Twenty-eight states have some form of "three-strikes" law. A person accused under such laws is referred to in a few states (notably Connecticut and Kansas) as a "persistent offender", while Missouri uses the unique term "prior and persistent offender". In most jurisdictions, only crimes at the felony level qualify as serious offenses; however, misdemeanor offenses can qualify for application of the three-strikes law in California, whose application has been the subject of controversy.

The popular name of these laws, three-strikes laws, comes from baseball, where a batter is permitted two strikes before striking out on the third.

The three-strikes law significantly increases the prison sentences of persons convicted of a felony who have been previously convicted of two or more violent crimes or serious felonies, and limits the ability of these offenders to receive a punishment other than a life sentence.

The practice of imposing longer prison sentences on repeat offenders (versus first-time offenders who commit the same crime) is nothing new, as judges often take into consideration prior offenses when sentencing. However, there is a more recent history of mandatory prison sentences for repeat offenders. For example, New York State had a long-standing Persistent Felony Offender law dating back to the early 20th century (partially ruled unconstitutional in 2010, but reaffirmed en banc shortly after). But such sentences were not compulsory in each case, and judges had much more discretion as to what term of incarceration should be imposed.

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